C.O.P/Refrigerator (Finding Temp)

  • Thread starter Thread starter HugoPang1
  • Start date Start date
AI Thread Summary
The discussion centers on calculating the surrounding room temperature based on the coefficient of performance (C.O.P) of a refrigerator operating at 0.98, which is 13% of the theoretical maximum. Given that the freezer compartment is at -12 Celsius, the relationship between the C.O.P, heat extracted (Qo), and work done (W) is crucial. The participants explore the Carnot cycle's efficiency, emphasizing that the highest C.O.P can be expressed in terms of the temperatures of the hot and cold reservoirs. The calculations suggest that the surrounding room temperature is approximately 295K. This analysis highlights the importance of understanding thermodynamic principles in real-world applications.
HugoPang1
Messages
3
Reaction score
0

Homework Statement



A refrigerator is operating at a C.O.P of 0.98, which is 13% of the max C.O.P theoretically possible. The temperature of the freezer compartment of the refrigerator is -12 Celsius. What is the temperature of the surrounding room (in Celsius)?

Homework Equations



C.O.P = Qo/W

The Attempt at a Solution



Cannot interpret the question correctly
 
Physics news on Phys.org
HugoPang1 said:

Homework Statement



A refrigerator is operating at a C.O.P of 0.98, which is 13% of the max C.O.P theoretically possible. The temperature of the freezer compartment of the refrigerator is -12 Celsius. What is the temperature of the surrounding room (in Celsius)?

Homework Equations



C.O.P = Qo/W

The Attempt at a Solution



Cannot interpret the question correctly
What kind of thermodynamic cycle would be the most efficient (highest COP)? What is the expression for that highest COP in terms of temperature of the hot and cold reservoirs? What is Qo?

AM
 
Assume Qo is energy taken from freezer and Q1 is energy released after each cycle. For Carnot process

T1/To equals Q1/Qo

Also W equals Q1 - Qo

In ideal case cop equals 0.98/.13, because we know in non ideal case cop is .98

But cop equals Qo/(Q1-Qo) take reciprocal hence get Q1/Qo, from which use relationship with T1 and To to get T1. Remember that To is 261. My answer is around 295K

Hope I haven't given too much away
 
I multiplied the values first without the error limit. Got 19.38. rounded it off to 2 significant figures since the given data has 2 significant figures. So = 19. For error I used the above formula. It comes out about 1.48. Now my question is. Should I write the answer as 19±1.5 (rounding 1.48 to 2 significant figures) OR should I write it as 19±1. So in short, should the error have same number of significant figures as the mean value or should it have the same number of decimal places as...
Thread 'A cylinder connected to a hanging mass'
Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
Back
Top